Something about these that's cropped up on the support board a few times (example support request) is what LiveJournal settings are required by a user wanting to post to their journal. Generally, they're using a Blogger API client. Different clients refer to the settings they require - usually a URL & username - by different names. The terms most frequently used, and enquired about, seem to be: 'RPC URL' or 'endpoint' and 'Blog ID'.
As the FAQ points out, users need to contact the client developer/documentation if they need help. I think it would be good if we could say something like LJ setting $foo will usually map to generic client option $bar though.
Example wordage (interface URL refers to existing one given in FAQ):
Terms used by different Blogger API clients for post settings do vary. Generic clients commonly require you to enter an 'RPC URL' / 'service endpoint' and a 'Blog ID'. The 'RPC URL' or 'service endpoint' is the interface URL given above, while the 'Blog ID' setting is normally your LiveJournal username.